A number of patents and publications are cited herein in order to more fully describe and disclose the invention and the state of the art to which the invention pertains. Each of these references is incorporated herein by reference in its entirety into the present disclosure, to the same extent as if each individual reference was specifically and individually indicated to be incorporated by reference.
Throughout this specification, including the claims which follow, unless the context requires otherwise, the word “comprise,” and variations such as “comprises” and “comprising,” will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers, or steps.
It must be noted that, as used in the specification and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a pharmaceutical carrier” includes mixtures of two or more such carriers, and the like.
Ranges are often expressed herein as from “about” one particular value, and/or to “about” another particular value. When such a range is expressed, another embodiment includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by the use of the antecedent “about,” it will be understood that the particular value forms another embodiment.
This disclosure includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
Lipopeptides
Secondary metabolites from microorganisms are successfully employed for the treatment of infectious diseases. Secondary metabolites are low molecular weight compounds whose production takes place in “biosynthetic oneway streets” which branch off from the primary metabolism, and whose function for the particular producer is unclear. The main area of use of these secondary metabolites is the therapy of infectious diseases. However, owing to the wide use, there is frequently development of resistance so that there is a continuous need for novel antibiotics and active substances with novel mechanisms of action (Neu H. C., Science 257, 1992, pages 1064-1073). A therapeutically adequate effect on penicillin- or methicillin-resistant strains (MRSA strains) which have developed further antibiotic resistances is often possessed only by glycopeptides such as vancomycin or teicoplanin. However, strains also resistant to these antibiotics are increasingly appearing (FEMS Microbiol. Lett. 98 (1992) 5 109 to 116).
Antibiotics from the class of the lipopeptides, which are characterized by a linear or cyclic peptide portion or a combination of both, with naturally and/or non-naturally derivatized and/or non-derivatized amino acids, with which a saturated or unsaturated acyl residue is connected, have been found in the past as effective against fungi and Gram-positive bacteria. One example of such a lipopeptide is Friulimicin B, shown below.

For the majority of these compounds, however, toxic properties are also known.
European Patent Application No. 0 629 636 proposes lipopeptides which have homologous amino acid sequences but different fatty acid residues (lipid portion) and which are synthesized by Actinoplanes sp. during the fermentation and released into the culture medium, as well as a process for isolating the lipopeptides from the culture medium, their purification and the use of the lipopeptides as pharmacological active substances, in particular against Gram-positive bacteria. However, these lipopeptides exhibit toxic properties, in particular hemolysis.
There remains a need to provide pharmacologically active substances that can be used in the treatment of bacterial infection, particularly resistant strains (e.g. MRSA), whilst avoiding the toxic effects discussed above.